Electrical switch



Aug. 14, 1962 R. w. FRASER 3,049,600

ELECTRICAL SWITCH Filed July 7, 1960 Iii a II J.

. Imveniav' 1202293? W. Fuusezq fizzy.

stares This invention relates generally to electric switches and more particularly to single pole, double throw snap switches.

An object of the invention is to provide a single pole, double throw snap switch wherein the armature bears against the single pole feed contact.

A further object of the invention is to provide a snap switch wherein the fulcrum of the armature carries current.

A still further object of the invention is to provide a snap switch having means allowing a comparatively substantial take-up for irregularities of tolerance in the assembly with which the switch is engaged.

Another object of the invention is to provide an electric snap switch in which the tension spring is in direct engagement with the actuator assembly and levers of the armature.

Other objects of the invention will, in part, be obvious, and will, in part, appear hereinafter.

In the drawing:

FIG. 1 is a side elevation with cover removed and plunger all the way down;

FIG. 2 is a side elevation with cover broken away and plunger all the way up;

FIG. 3 is a view in section taken on line 33 of FIG. 2;

FIG. 4 is a view in section taken on line 44 of FIG. 2;

FIG. 5 is a side elevation with cover removed and plunger part way down;

FIG. 6 is a side elevation partly in section; and

FIG. 7 is a view in section taken on line 77 of FIG. 6.

Referring to the drawing, there is illustrated an electric switch assembly 14 comprising a housing 12. The housing 12 is made of any suitable insulating material, in this instance a phenolic plastic was utilized. The housing 12 has a cap 14 having an aperture 16 formed therein, whose function will hereinafter be set out. The housing 12 is formed of two parts, a body 18 and a cover 29. The body 18 and the cover 253 are held together by any suitable means such as rivets, one of which is shown in FIG. 2, unnumbered, which are passed between the walls of aligned apertures in both the body 13 and the cover 20. The housing 12 is recessed as shown in FIG. 1 to provide an area in which the elements of the switch 12 can be placed. The body 18 also has a back wall 22 having slots 24 formed therethrough.

The switch mechanism comprises a pair of stationary contacts, a normal closed contact 26, and a normally open contact 28, a common feed contact 36, an armature 33, a tensioned coil spring and an actuator 42 having a compression spring 44. The normally closed contact 26 and the normally open contact 23 each comprise a fixed end portion 30 disposed through one of the slots 24, a free end portion 32 extending into the housing 12 and a support portion 34 connecting said fixed end portion 3t and said free end portion 32 and in angular relationship with them. Said fixed end portion 30 and said free portion 32 lie on planes in spaced parallel relationship with each other, as illustrated in FIG. I. Said feed contact 36 comprises a support element 46, having a greater length than said stationary contacts, disposed through the bottom slot as shown in FIG. 1, and a bearing arm 48 in the form of a rectangular frame and in integral right angle relationship with said support element 46. The sides 50 of said bearing arm 48 are in right angle relationship with said "ice support element and in spaced relationship with each other. Each of said sides 50 has a notch 52 formed therein.

The said armature 33 is U-shaped and comprises a pair of spaced arms 54 interconnected at one end thereof by a bight portion 56. A double faced contact button 58 is carried on said bight portion 56 for engagement either above or below said armature 3S and said armature arms 54 are notched at their free ends. A small aperture is formed on the midline of said bight portion 56 directly in front of said contact button 58 as best shown in FIG. 1.

The actuator 42 comprises a tubular plunger 60 open at one end and a flanged eyelet 62 open at both ends. A rectangular abutment 64 formed at the open end of said actuator 42 has a greater width than the remaining portion of said actuator 42 forming two shoulders 66. One of the narrower sides of said abutment 64 is left open to form a pass-through 68 as best illustrated in FIG. 6. The eyelet 62 comprises a tubular shank 76 open at both ends and having a flange 72 in integral, angular relationship with one of said ends.

The tension spring 40 has a loop 74 formed at one end, of slightly greater diameter than the tubular shank 70, of the eyelet 62 and at its opposite end a hook 7 6 is formed. To assemble the switch 10, the two fixed contacts are placed in the housing 12 as hereinbefore set forth, the said two free end portions 32 in substantially parallel spaced relationship. The hook 76 is engaged with the wall of the aperture formed in the bight 56 of the armature 38 and the shoulders formed by the notches on the arms 54 of the armature 38 are engaged with the shoulders formed by the notches 52 of the sides 51 of the bearing arm 43. At this juncture the major portion of the tension spring 40 lies between the arms 54 of the armature 38 and the loop 74- of the said tension spring 40 having been passed between the sides 50 of the bearing arm 48 is looped around the said tubular shank 7t) abutting the flange of the said eyelet 62. The feed contact 36 with the assembly of the armature 38, the tension spring 40 and the eyelet 62 are placed in position in the housing 12 as best illustrated in FIG. 6. The compression spring 44 is passed between the walls of the tubular shank 70 of the eyelet 62 until one of its terminal ends rests against a recess formed in the base of the housing as shown in FIG. 6 and the other end of said compression spring 44 is passed into the tubular portion of the plunger 6%. The plunger 60 has an internal shoulder formed on the inside wall of said rectangular abutment 64 against which the loop 74 abuts. The eyelet 62, assembled as herein set forth, is passed between the walls of said rectangular abutment 64 until said flange 72 abuts the surface adjacent the open terminal end of said plunger 60 and the tension spring 49 passes between the walls of said pass-through 68. At this stage the armature 38 is directly connected to the actuator 42 by the tension spring 40. The contact button 58 and the contact buttons of the back and tool feed contacts 26 and 28 are made of silver, although any good electrical conductive material would suffice.

The plunger 60 is passed through the cap 14 between the walls of the aperture 16 allowing the plunger to move freely between the walls of the said aperture 16 so that it may be depressed and released. There are many methods whereby the switch assembly 10 could be engaged to an apertured support 84}. Applicant has shown a fastener element 78 of the heel and toe variety, old in the art, which can be snapped into the apertured support to accomplish the engagement of the switch assembly with the support.

As shown in FIG. 7, the tension spring 40 holds the armature 38 in a raised or open position, as an axial force is applied to the actuator 42 tension is increased on the tension spring 40 until a predetermined portion of said tension spring 40' has passed the notches 52 formed in the bearing arm 48 at which time the armature 38 is snapped toward the normally open contact 28 and electric engagement is made. Note that the points of engagement between the armature 38 and the bearing arm 48, which points may conveniently be called fulcrum points, are energized and part of the circuit. After engagement of the armature 88 and the bearing arm 48, the compression spring 44 can be compressed for a comparatively substantial distance to act to provide a take-up or traveL Since certain other obvious modifications may be made in this device without departing from the invention, it is intended that all matter contained herein be interpreted in an illustrative and not in a limiting sense.

I claim: I

An electrical switch comprising a housing provided with an interior recess, at least one fixed contact mounted within said recess and having at least two inner walls defining an actuator channel, each of said inner walls having a height substantially equal to the height of said housing, an armature comprising a pair of spaced arms connected at one end thereof by a bight portion, said bight portion having an electrical contact means, an actuator directly connected with said bight portion by a tensioned coil spring, said coil spring having a hook element, said actuator comprising a plunger having a wall forming an internal bore, a compression spring, and an eyelet, said eyelet having a tubular shank and a flange, said hook element of said tension coil spring circumscribing said tubular shank and being held between said flange and said plunger, said switch having a feed contact comprising a pair of legs in spaced relation with each other and with said actuator, said arms of said armature pivoted against said legs of said feed contact, a portion of said coil spring passing between said arms and another portion of said coil spring passing between said legs, said actuator having a compression spring associated therewith to return said actuator to a normal position from a second position and the point of said pivoting engagement forming a part of the switch circuit.

References Cited in the file of this patent UNITED STATES PATENTS 1,709,944 Loranger Apr. 23, 1929 1,877,327 Ingersoll Sept. 13, 1932 1,893,875 Aldrich Jan. 10, 1933 2,779,835 Russel Jan. 29, 1957 2,810,030 Ball Oct. 15, 1957 2,813,943 Winter Nov. 19, 1957 FOREIGN PATENTS 117,467 Australia Sept. 3, 1943 

